Y2K Problem, MillenniumBug - OHS Implications

23. (1998)

Introduction

Most people and managers are aware of the Year 2000 (Y2K) date problem - or Millennium Bug - and the challenges it presents to computer systems and information technology generally. For many computer and software systems the Year 2000 will bring a host of problems related to software programs which record the date using only the last two digits of each year.

Many people are not aware that there are other important aspects to the Year 2000 date problem - many of which have significant implications for occupational safety and health. While most Y2K strategies have focused on fixing software-based computer systems, embedded systems (which use preprogrammed chips rather than modifiable software) have received very little attention. Embedded systems (sometimes called Process Logic Control or PLC) generally comprise some type of microprocessor or digital electronics, often with a timer, and are 'embedded' or built into modern equipment, controlling everything from lifts and air conditioning to medical equipment and nuclear reactors. Any embedded system which is "date aware" is likely to be affected by the Y2K problem.

The purpose of this document is to provide a brief overview of the Y2K problem as it relates to occupational safety and health and to recommend active management of the risks arising from equipment and other failures that may occur.

Year 2000 Problem

In simple terms the Y2K problem is the result of obsolete programming assumptions. Because of the need to save space in early computer systems, programmers abbreviated dates using 2 digit numbers for the year instead of 4 digit numbers. Software programs that use dates in the 2 digit format will have problems counting days following 31 December 1999. Some will halt with an error message when they fail to find a 2-digit number that equals 99 + 1. Others will record the date as 01/01/00 but process it mathematically as 1 January 1900 rather than 1 January 2000. These programs will generate data improperly.

Specific date changes that may cause problems are:-

• 1 January 1999;
• 9 September 1999 (9/9/99);
• 31 December 1999 to 1 January 2000;
• 28 February 2000 to 29 February 2000;
• 29 February 2000 to 1 March 2000;
• 30 December 2000 to 31 December 2000;
• 31 December 2000 to 1 January 2001

Embedded Systems

All of the problems evident with 2 digit dates in computer software are applicable to those embedded systems which are "date aware". However, unlike software problems - which can usually be fixed through program modifications - the problems in embedded systems are more complex and may involve difficulties with a combination of hardware, application software and operating systems.

In many cases embedded systems operate independent of other equipment to which they are connected, making it extremely difficult to effectively address Year 2000 problems. Embedded systems typically use many intelligent input/output devices which themselves may not be Y2K compliant. The potential exists for many systems and components to fail at the same time. Finding and fixing Y2K problems in embedded systems under these circumstances can be extremely difficult.

Difficulties likely to be encountered with embedded systems include:-

• microprocessors which use only 2 digits for date calculations may generate unanticipated errors after 31 December 1999, if one day is subtracted from another during a program process;
• some microprocessors will interpret the date 01/01/00 as 1 January 1900 - a Monday rather than a Saturday;
• some microprocessors may not recognise that the Year 2000 is a leap year, which may result in the incorrect identification of days of the week after 28 February 2000.

While some of these problems may lead to process failures, which are merely inconvenient, other system, plant and equipment failures and malfunctions could have serious safety and health implications. These implications may include:-

• shut down of key systems, plant or equipment;
• failure of systems, plant or equipment to respond correctly to pre-programmed situations, in particular the execution of emergency action;
• unsafe action being taken by systems, plant or equipment;
• lack of action being taken by systems, plant or equipment.

Key workplace systems, plant and equipment that may be effected by these problems, include:-

• generic process control equipment and control panels;
• fire and smoke detection systems, alarms and automatic fire extinguishers;
• emergency and access lighting;
• emergency power;
• environmental control systems (air-conditioning, refrigeration, heating systems);
• waste treatment, atmospheric emission control, etc;
• security and safety lock off systems;
• transportation control and signal systems;
• pumps and level control systems;
• cooling water
• temperature control systems;
• PABX and other communications equipment;
• emergency systems;
• air conditioning;
• lift controls;
• video and audio equipment.

Occupational Safety and Health

Failures in embedded systems in workplaces could lead to significant occupational safety and health problems. Under occupational safety and health legislation employers have a duty of care to ensure employees are not exposed to hazards at work - including hazards that may arise from the failure of embedded systems.

Occupational safety and health legislation also places duties on persons who have control of a workplace to ensure that access to and egress from a workplace is safe. They must also ensure the workplace is safe for any visitors or other people at the workplace. These duties may apply to anyone with a contract, lease or other obligation to maintain or repair the workplace or its access and egress. Responsibility for systems such as lifts and air-conditioning may rest with building owners or managers rather than employers.

Similarly, people who design, manufacture, import or supply plant containing embedded systems for use at workplaces have a duty to ensure that the article is designed, manufactured and marketed so that people installing, maintaining or using it properly are not exposed to hazards.

To be certain of complying with their duty of care, employers, manufacturers and designers must actively seek to identify any Y2K problems associated with embedded systems they use, manufacturer or design. In most cases a detailed and thorough Y2K date change management approach is essential as even seemingly inconsequential faults may have devastating results. For the University, these processes are being coordinated through Nigel Woods, IT Services, but Area management remains fundamentally responsible for any OHS implications.

Further Information

Detailed information on how to manage the year 2000 date change can be found in Standards Australia 's Code of Practice SAA HB120-1998, Managing Year 2000 Conformity.

A comprehensive approach to occupational health and safety and the Year 2000 problem has been developed by the Health and Safety Executive (HSE) in the United Kingdom. The HSE publication Health and Safety and the Year 2000 Problem recommends a risk management approach to Y2K safety issues. The HSE publication includes guidelines for identifying hazards (investigation), assessing risks (planning) and implementing changes (rectification), and suggests ways of managing the process.

The Western Australian Government has published a Millennium Compliance Guide and other information on managing the Y2K problem (see www.y2k.wa.gov.au). Additional online information on occupational safety and health issues associated with embedded systems is available from the Institution of Electrical Engineers (UK) (see www.iee.org.uk/2000risk/).

References

Department of Employment, Training and Industrial Relations, Division of Workplace Health and Safety, The Year 2000 problem — how it affects health and safety.

For further information contact:
OHS Officer, e-mail: OHS.Officer@anu.edu.au